In the past, in a semiconductor device (LSI: semiconductor integrated circuit), a resistance device is made using, for example, polycrystalline silicon (“poly-silicon”) formed on a silicon substrate.
Such a poly-silicon resistance device (poly-silicon resistor) includes the advantages of having a higher sheet resistance than a resistance device using copper (Cu) or aluminum (Al) and of having a smaller fluctuation in resistance than a resistance device using a diffusion layer of a silicon (Si) substrate.
However, since a poly-silicon resistor includes a high sheet resistance, it generates a large Joule's heat per current and, for example, is liable to cause a drop in the reliability of a Cu interconnect which is provided near the poly-silicon resistor.
In this regard, in the past, various proposals are made for semiconductor devices which are designed to disperse heat from resistance devices to thereby suppress a rise in temperature in the surroundings.
Patent Document 1: Japanese Laid-open Patent Publication No. S63-090846
Patent Document 2: Japanese Laid-open Patent
Patent Document 3: Japanese Laid-open Patent Publication No. 562-040757
Patent Document 4: Japanese Laid-open Patent Publication No. 2000-031484